John Bercow

As speaker, Bercow is in charge of House of Commons business and therefore has the power to choose which amendments MPs vote on.

During the vote on the government’s legislative agenda, he picked a Labour rebel amendment tabled by Chuka Umunna calling for Britain to stay in the single market post Brexit, and one by Labour’s Stella Creasy on NHS abortions that caused headaches for the government.

PARTY: Conservative

POSITION: Speaker of the House of Commons

MP SINCE: 1997

REMAINIAC OR BREXTREMIST? Remain

Return to the full list of 40 Brexit troublemakers to discover who to watch as legislation disentangling Britain from the European Union goes through the U.K. parliament. For an explanation of how this list was compiled, see here.